For there to be any kind of real “civil war” there would need to be a very clear distinction between sides and goals alongside states declaring

That’s how the US Civil War happened, but frequently a national Civil War does not have such clear boundaries and sides. See Syria for a very messy conflict where about the only thing defining one ‘side’ was ‘not Assad’ and very little agreement other than that.

Civil war would be the worst possible outcome to be sure, but a messy situation can just as easily feed a civil war.